Coral reef diseases have been discovered since the 1970s in ever-increasing numbers and varieties around the world accounting for the destruction and death of many species of coral and entire coral reefs. Coral reef disease is attributed to global warming, climate change, and the pollution of the water around coral reefs.
Coral cannot exist or thrive in nutrient rich water caused by pollution or in waters that are too warm. Corals live in a complex symbiotic system that relies on exact water temperatures, photosynthesis from the sun, and the general health of all organizms within the coral reef ecosystem.
The exact cause of these diseases is still being researched. Many are attributed to a bacterial agent, but evidence in most cases is inconclusive.
Major coral reef diseases:
Nuisance algae (macroalgal growth)
Nuisance algae are affecting the endangered elkhorn and staghorn corals in Florida, Puerto Rico, St. Thomas/St. John, and St. Croix. According to NOAA fisheries the cause is the lack of herbivores and sea urchins, however Reef Relief claims NOAA has failed to include pollution of the waters, which is causing a high nutrient content; and water temperature. Corals do not thrive in nutrient dense waters caused by pollution or in waters that are too warm or too cold. Global warming, climate change, and pollution of the waters are the main causes for this disease and therefore The Center for Biological Diversity has filed a suit on behalf of this condition. Read more about this at Reef Relief.
Yellow blotch disease (YBD)
YBD affects the star coral and brain coral. It was first spotted in 1994 and exists in the Florida Keys and the entire Caribbean. The exact cause is unknown at this time. Further research is necessary.
White plague
White plague was first discovered in 1977. There are three types – types I, II, and III. Tissue death is greatest in types II and III. Type I affects 10 coral species. Type II affects 33 species. Type III affects the largest reef building corals.
White-band disease (WBD)
WBD was first discovered in 1977. It affects the elkhorn and staghorn corals and is found in St. Croix, the Caribbean, the US Virgin Islands, nine countries in the Indo-Pacific region, the Great Barrier Reef, and Indonesia. WBD is responsible for “major change in reef structure.”
Red-band disease (RBD)
There are two types of RBD. They affect massive plating, stony corals, and sea fans in the Caribbean.
Dark Spots Disease (DSD)
This coral disease was first spotted in the late 1990s. DSD is found in Colombia, the Florida Keys, the Caribbean, and the Western Atlantic. DSD affects massive reef-building coral, massive starlet coral, and blushing star coral.
Coral Bleaching
Bleaching has been known since the early 1900s, but has proliferated since the 1980s. It affects numerous species worldwide and was first discovered in 1972 in Belize and Florida. It is now known to affect 26 countries including Fiji, the Phillipines, Australia, and Western Atlantic.
Bleaching affects massive reef-building coral, stony coral, and sea fans. It affects 16 species in the Western Atlantic and 26 species in the Red Sea and the Indo-Pacific regions.
References:
http://www.reefrelief.org/reefreliefnews/reefnews.asp?file=EndSpeciesListing.html
http://coris.noaa.gov/about/diseases/
